What's the type of `{ "abc" }`

Question

Scala code:

{ "abc" }

What the type of it? Is it => String, or just String?

Related: http://stackoverflow.com/questions/4386127 – Robert Harvey Aug 20 '14 at 17:39 — Robert Harvey, Aug 20 '14 at 17:39

score 3 · Answer 1 · answered Aug 20 '14 at 18:44

Maybe it's worth saying that the type of the block is the type of its result expression.

More or less.

The expected type of the final expression e is the expected type of the block.

That's the case (obviously) for f { "abc" }. You get conversions based on the param type to the function.

Gabriele Petronella · Answer 2 · 2014-08-20T19:11:42.130

1

It's a String

scala> { "abc" }
res0: String = abc

edited Aug 20 '14 at 19:11

answered Aug 20 '14 at 17:40

I can't pass `{ () => "abc" }` to a method `def print(s: => String)`, but can pass to `def hello(s: ()=> String)` – Freewind Aug 20 '14 at 17:57
1

@Freewind that is compiler "magic", as explained in great details here: http://stackoverflow.com/a/25409347/846273 – Gabriele Petronella Aug 20 '14 at 18:17
`() => String` and `=> String` are different, so I don't understand why you conflate them. – som-snytt Aug 20 '14 at 18:37
@som-snytt they're roughly equivalent, however it's probably not accurate to treat them as they were the same. I'll take that bit away. – Gabriele Petronella Aug 20 '14 at 19:11

2 Answers2